In gene therapy, a defective gene is replaced by a virus carrying a normal gene. If successful, 1. The cells divide and daughter cells express the normal gene.
2. The cells are recycled after death.
3. The cells lack a nucleus.
4. The cells do not produce the normal gene.

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

b. heterotroph

explanation:

what are the options? add them, then i will be glad to .